THE BBC has officially taken the 'light' out of light entertainment. On Monday it announced the appointment of David Liddiment as head of the Entertainment Group for Television, replacing Jim Moir, head of the Light Entertainment Group.

In the BBC, such textual detail is never without significance and this one illustrates the corporation's continuing indecision about exactly where to target its programmes. Mr Liddiment himself is an unashamed populist - at Granada he was responsible for such shows as You've Been Framed and Stars In Their Eyes. So to quell fears of rampant game and 'people' shows, he has been given a less flippant title.

Mr Liddiment lives in Manchester, so he would not be a reader of the South London Press. Before he arrives at the BBC, though, he should get a copy of last week's issue and turn to an interview with the comedian Ronnie Corbett.

He was bemoaning the lack of popular television comedy programmes like the ones he used to star in. He said that nowadays there was one audience for Channel 4 and BBC 2 and another for the more popular channels, and their tastes did not meet. 'People don't sit down and watch one programme any more like they did with Eric and Ernie,' he said.

Mr Corbett is right. Television viewing has polarised, but the BBC's controllers do not acknowledge it. They believe that the homogeneous Morecambe and Wise family audience does still exist, if only the programmes can be found to reach it.

That is why they are super-sensitive about the vocabulary used to discuss their programme strategy. This month Liz Forgan, managing director of BBC Radio, said that the upper socio-economic groups, the ABC1s, were being oversupplied with goodies by the BBC, and Alan Yentob, controller of BBC1, said he wanted to do more for the C2s and Ds. They were surprised and annoyed that the press interpreted that as an intention to move 'down-market'.

BBC people despise that word because they think it implies that they are going for tacky programmes that appeal to readers of the Sun. They prefer to say that they are trying to 'engage' (a favourite BBC word) viewers of all classes.

When Charles Denton, the new head of drama, addressed the issue last week, he unveiled the new politically correct word for the target audience - the 'mainstream'. And Mr Liddiment, on his appointment, said he was seeking 'shows with broad popular appeal'.

The insistence on the BBC's universality stems from the debate that has been going on for years about the proper role of a public broadcaster. Should it restrict itself to the high ground, producing only programmes of serious intent that are unprofitable for commercial broadcasters? Or must it, to earn its public funding, engage the mainstream?

The document Extending Choice, published when John Birt became the BBC's director-general in January, fudges that central issue. Although it commits the BBC to airing 'all forms of entertainment, humour, artistic and cultural expression', it adds that it should withdraw from 'derivative formula or entertainment formats' and 'simple and unchallenging game shows and people shows'.

That is having it both ways. If you are going to show all forms of entertainment, you must include game shows, enjoyed by large numbers of those C and D viewers that Mr Yentob says he wants to reach.

The Liddiment appointment suggests that this is what will happen but the latest programme plans - the autumn and winter drama schedules announced last week - retain a distinctly up-market bias, with little to satisfy what a report last week from the Henley Centre called the 'cultural underclass', who watch television because they cannot afford to go out and do anything more interesting.

With more and more channels offering narrowly targeted programmes, it seems unlikely that Mr Liddiment will find anything to approach the cross-cultural appeal of Eric and Ernie, and it may be futile to try. When Alan Yentob unveils BBC 1's autumn schedule next week, we shall be able to judge whether the long-delayed decision about going up or down-market has finally been faced, even if he still flinches at the vocabulary.